Programming Web Services with XML-RPC

Chapter 4. XML-RPC and Perl

XML-RPC and the Perl scripting language are a particularly powerful combination for creating flexible web services rapidly. Perl has long been the language of choice to obtain and manipulate data for the Web, and it is moving into the growing field of web services. One of Perl’s guiding philosophies is “Easy things should be easy, and hard things should be possible.” The Perl module for XML-RPC, Frontier::RPC, embodies this.

To show how easy Perl’s XML-RPC library, Frontier::RPC, makes remote procedure calls, consider the following code snippet:

use Frontier::Client;
my $client = Frontier::Client->new 
           ( url => "http://example.com:1080");
print "helloWorld('Bob') returned: ",
           $client->call('helloWorld', 'Bob'), "\n";

Assume that on a machine called example.com, there is an XML-RPC server running on port 1080 that has implemented a procedure named helloWorld( ). Given these assumptions, these three lines of Perl code are all that’s needed to make an XML-RPC call. Although this chapter explores the details of using this library more thoroughly, many XML-RPC Perl clients aren’t any more complicated than this example.

This chapter begins with a discussion of the history, requirements, and architecture of Perl’s XML-RPC library, Frontier::RPC. Then it covers how to create XML-RPC clients and servers using Perl, including instructions for running an XML-RPC server from a web server.

Perl’s Implementation of XML-RPC

As of this writing, there’s only one XML-RPC ...